Hollow-core slabs, sometimes referred to as voided slabs or hollow core planks, are precast slabs of concrete. They are often used in building constructions, for example, as floors, walls or roofs in multi-story buildings. The precast concrete slab typically has tubular voids extending the full length of the slab, making the slab lighter than a massive floor slab of equal thickness or strength. Reduced weight lowers material and transportation cost.
Typical slabs are about 120 cm wide with a standard thickness between 15 cm and 50 cm. The precast concrete I-beams between the holes contain steel wire ropes that provide bending resistance to bending moment from loads. The manufacturing process involves extruding wet concrete around the prestressed steel wire rope from a moving mold. After curing the continuous slab is cut according to the required lengths and width. Hollow-core floor slabs are also made in rebar reinforced concrete (not prestressed). Hollow-core wall panels are made without reinforcement.
Most hollow-core slabs manufactured today are made from conventional concrete. For the most part, existing concrete hollow-core slabs are operative and reliable for the intended purposes. Concrete hollow-core objects, however, are not optimal in terms of both economics and environmental impact. Existing production technologies involve large energy consumption and carbon dioxide emission, leading to unfavorable carbon footprints.
Thus, there is an on-going need for novel hollow-core objects prepared from composite materials that match or exceed the physical and performance characteristics of conventional hollow-core objects manufactured using conventional concretes, and that can be mass-produced at lower cost with improved energy consumption and more desirable carbon footprint.